title: Cross-reactions between mouse Ia and human HLA-D/DR antigens analyzed with monoclonal alloantibodies.
abstract: Two mouse monoclonal anti-I-E/Ck alloantibodies (H7-8.26 and H10-81.10) directed against 2 distinct determinants of the specificity Ia-7 and 1 anti-I-Ak alloantibody (H8-15.9) directed against a public determinant common to the I-A subregion products of the H-2k, H-2b, H-2d, H-2q, and H-2ja haplotypes identified cross-reactive determinants on lymphoid cells from various mammalian species, including rat, dog, pig, cow, hamster, and guinea pig. In man, these antibodies detected nonpolymorphic determinants of DR antigens on B cell-enriched peripheral blood lymphocytes from 50 unrelated individuals. These cross-reactive DR determinants were also detected on lymphoblastoid B cell lines, on PHA-activated peripheral T lymphocytes, and on allospecific cytolytic T cell clones, but not on various DR-negative human T leukemia cell lines. Two chains of 29,000 and 35,000 daltons m.w., corresponding to DR antigens, were precipitated by H7-8.26 and H8-15.9 antibodies from radiolabeled membrane extracts of Raji cells. Competitive binding experiments indicated that the 3 mouse anti-Iak antibodies identified 3 distinct cross-reactive determinants on human cells. The results indicate that: a) The cross-reactivity described between mouse I-E/C gene products (Ia-7) and human DR antigen(s) involves, in fact, several distinct and topologically distant determinants. b) At least 1 determinant cross-reacting with DR can be identified on I-Ak gene products. c) The intriguing genetic problem of mouse MHC allotypic determinant(s) being nonpolymorphic in man cannot be simply explained by the deletion of an I-E alpha chain in some strains of mice.
mesh_terms: D000042:Absorption; D000818:Animals; D000906:Antibodies; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology; D001667:Binding, Competitive; D002417:Cattle; D002460:Cell Line; D011232:Chemical Precipitation; D002999:Clone Cells / Q000276:immunology; D006224:Cricetinae; D003429:Cross Reactions; D006168:Guinea Pigs; D000949:Histocompatibility Antigens Class II; D006801:Humans; D051379:Mice; D011817:Rabbits; D051381:Rats; D013552:Swine; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000906:Antibodies; D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II